FILE - The damage from the fertilizer plant explosion is seen from helicopters in accompanying President Barack Obama in West, Texas, in this April 25, 2013 file photo. The U.S Chemical Safety Board

... more 

FILE - The damage from the fertilizer plant explosion is seen from helicopters in accompanying President Barack Obama in West, Texas, in this April 25, 2013 file photo. The U.S Chemical Safety Board will tell a Senate committee Thursday June 27, 2013 that regulation of the dangerous chemicals used in the industry fall under a “patchwork” of standards that are decades old and are far weaker than rules used by other countries. The findings will be presented to the U.S. Senate Committee on Environment and Public Works. (AP Photo/Charles Dharapak, File) less 

1 / 16
Associated Press
Thu, Jun 27, 2013 10:17 PM EDT